The present invention relates to a separator for a fuel cell that has gas passages for fuel gas and oxidation gas.
This type of separator has gas passages. In this case, to enable efficient power generation, gas preferably evenly flows in the gas passages.
Japanese Laid-Open Patent Publication No. 2009-59685 discloses a configuration having gas passages and parts of enlarged and reduced cross-sectional flow areas on the upstream side and the downstream side of the passages. The publication describes that gas is caused to pass through these parts so that the evenness of gas distribution to the gas passages is improved.
The separator of the publication includes coupling passages located on the upstream side and the downstream side of the gas passages, and each coupling passage has a part of an enlarged cross-sectional flow area and a part of a reduced cross-sectional flow area. As a result, the gas passages are elongated, which in turn increases the size of the whole separator.